Increased cerebrospinal fluid interleukin-6 levels in patients with schizophrenia and those with major depressive disorder

Abstract

Elevated peripheral levels of interleukin-6 (IL-6) are common findings in schizophrenia and depression. However, previous studies that measured cerebrospinal fluid (CSF) IL-6 levels in these disorders reported controversial results. The present study examined whether CSF IL-6 levels are altered in patients with schizophrenia and those with depression. Lumbar punctures were performed in 32 patients with schizophrenia, 30 with major depressive disorder (MDD), and 35 healthy controls.Serum samples were simultaneously collected from all subjects in the patient groups and from 32 of the control group. CSF and serum IL-6 levels were determined by enzyme-linked immunosorbent assay. Both the patients with schizophrenia and MDD had significantly higher CSF IL-6 levels compared to the controls (schizophrenia: P = 0.0027; MDD: P = 0.012). IL-6 levels were significantly higher in the CSF than in the serum. No significant correlation was observed between CSF and serum IL-6 levels.One limitation of the study was the different smoking prevalence between patient groups and controls, which may have confounded the findings for MDD patients. In all, the present findings suggest that IL-6 of central origin is associated with the pathophysiology of schizophrenia and MDD.

Infectious diseases, IL6 −174G > C polymorphism, and human development

“…Also, elevated levels of IL6 have been found in Bipolar disorder, Schizophrenia and Intellectual Disability (Brietzke et al, 2011;Potvin et al, 2008;Sasayama et al, 2013;Aureli et al, 2014). Accordingly, we found strong positive correlations between IL6 À174G frequency and 2004 WHO DALYs for Bipolar Disorder (r 81 = 0.800, P < 0.001) and for Schizophrenia (r 81 = 0.653, P < 0.001).…”

“…Consistent with this evidence, elevated levels of IL6 have been found in Bipolar disorder, Schizophrenia and Intellectual Disability (Brietzke et al, 2011;Potvin et al, 2008;Sasayama et al, 2013;Aureli et al, 2014). Additionally, higher IL6 concentrations have been associated with an increased rate of cognitive decline in both executive function and memory function among the elderly (Mooijaart et al, 2013).…”

Increased levels of IL-6 in the cerebrospinal fluid of patients with chronic schizophrenia — significance for activation of the kynurenine pathway

“…13 A few studies have also shown that CSF IL 6 is elevated in patients with chronic schizophrenia. 14,15 Al though evidence of immune activation in schizophrenia is emerging, its functional relationship to aberrant brain neuro transmission and behaviour has been unclear. Activation of the kynurenine (KYN) pathway has been suggested as a mech anism serving to transfer information from the immune sys tem of the brain to neurons.…”

Envolvimento Da Flora Intestinal Na Modulação De Doenças Psiquiátricas

“…Muitos pacientes esquizofrênicos também apresentam distúrbios gastrointestinais, evidenciando um possível envolvimento da composição da microbiota intestinal na patofisiologia da doença (146)(147)(148). Além disso, vários estudos têm demonstrado que o sistema imunológico está desregulado em pacientes esquizofrênicos, além de haver uma correlação entre o risco de desenvolver esquizofrenia e genes relacionados com o sistema imunológico (149)(150)(151)(152)(153), sugerindo uma possível modulação da flora intestinal. Nestes pacientes, citocinas pró-inflamatórias (ex.…”